Polydopamine@SnS/g-C3N4 heterojunction photocatalyst: Insight into visible-light-induced reactive oxygen species (ROS)-mediated antibacterial and antimold activities

Photoresponsive CuS@polyaniline nanocomposites: An excellent synthetic bactericide against several multidrug-resistant pathogenic strains

“…The disruption of the antioxidant defense system leads to the degradation of cell proteins, disruption of lipid metabolism, and damage to the DNA within the cell wall, which ultimately disrupts microbial evolution and survivorship. 38,87 In this study, we propose the photocatalytic mechanism of the CuS@PANI NCs upon visible light illumination, which is significantly enhanced due to the synergistic effect between CuS and PANI. The reduction potential of the conduction band (CB) and valence band (VB) of CuS can be calculated using the following relationships of the Mulliken electronegativity theory.…”

“…The reduction potential of the conduction band (CB) and valence band (VB) of CuS can be calculated using the following relationships of the Mulliken electronegativity theory. 38 E VB = X − E C + 0.5 E g E CB = E VB − E g where E g represents the energy band gap, E C corresponds to the scaling factor (4.50 eV) that links the absolute vacuum scale with the normal hydrogen scale, and X signifies the average electronegativity of the constituent atoms of the semiconducting materials (approximately 5.27 eV for CuS). The as-determined CB and VB edge potentials of the CuS are respectively designed as −0.55 V and 2.08 V. These values indicate that the redox potential of the CB-electrons is sufficiently negative in comparison with the redox potential of 1M aqueous solution of molecular dioxide (O 2 /˙O 2 − , E ° = −0.17 V) and oxygen (O 2 /˙O 2 − , E ° = −0.34 V), which is in accordance with its band structure.…”

“…The as-determined CB and VB edge potentials of the CuS are respectively designed as −0.55 V and 2.08 V. These values indicate that the redox potential of the CB-electrons is sufficiently negative in comparison with the redox potential of 1M aqueous solution of molecular dioxide (O 2 /˙O 2 − , E ° = −0.17 V) and oxygen (O 2 /˙O 2 − , E ° = −0.34 V), which is in accordance with its band structure. 27,38 It is evident that the energy band positions of CuS ( E g = 2.63 eV, E CB = −0.55 eV, and E VB = 2.08 eV) and the conducting PANI with a visible bandgap, 50 are suitable for efficient separation and transport of the photogenerated charge carriers under visible light, which effectively promote the photochemical conversion of the surface adsorbed oxygen molecules into the cytotoxic ROS. As depicted in Fig.…”

“…The interaction between these ROS radicals and the cellular components of the bacteria results in notable cytotoxicity and damage to the bacterial cells. 38,75,76 It is crucial to comprehend the antibacterial mechanism responsible for the suppression of bacterial growth, and numerous informative studies are highlighting the toxicity of nanomaterials against various MDR microorganisms. [76][77][78][79][80][81][82][83] The primary convincing mechanism involves the direct interaction between antibacterial compounds and the cell wall of a bacteria, leading to cell membrane damage and inhibition of the bacterial growth.…”

“…37 Yuan et al , have reported a similar bactericidal performance in their study using a PDA@SnS/g-C 3 N 4 heterogeneous system for the effective treatment of several MDR pathogens under visible-light-induced ROS treatment. 38 Another investigation on the synthesis of a complex structure was conducted by Zhang's group, in which they observed enhanced antibacterial properties for the RGO/MoS 2 /Ag 3 PO 4 hybrid nanocomposite in contrast to its pristine components, due to the synergistic effect among the constituents. 39 Among these functionalization processes, the combination of conducting polymers and inorganic nanomaterials (polymers@inorganic) can be an attractive strategy to improve the biocidal activity of the neat CuS NPs.…”